204311161531 has 4 divisors (see below), whose sum is σ = 204340368352. Its totient is φ = 204281954712.

The previous prime is 204311161477. The next prime is 204311161547. The reversal of 204311161531 is 135161113402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204311161531 is a prime.

It is a super-2 number, since 2×204311161531² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204311161531.

It is not an unprimeable number, because it can be changed into a prime (204311161031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14592915 + ... + 14606908.

It is an arithmetic number, because the mean of its divisors is an integer number (51085092088).

Almost surely, 2^204311161531 is an apocalyptic number.

204311161531 is a deficient number, since it is larger than the sum of its proper divisors (29206821).

204311161531 is an equidigital number, since it uses as much as digits as its factorization.

204311161531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29206820.

The product of its (nonzero) digits is 2160, while the sum is 28.

Adding to 204311161531 its reverse (135161113402), we get a palindrome (339472274933).

The spelling of 204311161531 in words is "two hundred four billion, three hundred eleven million, one hundred sixty-one thousand, five hundred thirty-one".